Science Issues in Mold Litigation

Elizabeth B. Davis
Brian E. Heim
Stan B. Green

Mold and the health impacts and property damage it may allegedly cause are rapidly gaining public attention. Publicity from the media and debate within the scientific and legal communities have prompted significant litigation surrounding mold and its alleged health effects, and the number of mold-related insurance claims are on the rise. Through the increased litigation, the debate among medical and legal experts rages. At the same time, many state and federal legislators across the country are working to develop some structure to protect against mold-related impacts.

For the uninitiated, mold is a type of fungus that occurs naturally both indoors and out. Indoor molds can develop outdoors and travel indoors or develop indoors. Molds that originate outdoors travel indoors through open doors, windows or ventilation systems (either airborne or on clothing or other items). Molds also can originate indoors if they have a moist environment, oxygen and organic material on which to feed. Molds have no chlorophyll and cannot produce their own food. Common carbon-based construction materials can serve as a food source for mold, including drywall, insulation, carpets, drapes and glues. See, Harriet A. Burge et al., Moisture, Organisms, and Health Effects in Moisture Control in Buildings, 84-85 (Heinz R. Treschel ed., 1994).

Concerns regarding indoor air quality have grown in recent decades. One reason is the change in building construction. Partly in response to the energy crisis in the 1970s, today's building construction is tighter and more energy efficient, and modern construction relies less on the introduction of fresh outside air. These factors, when combined with excessive moisture, can contribute to the potential for increased biological contaminants such as mold and fungi in indoor air. When presented with opportunistic conditions of low airflow and high moisture, mold can develop and flourish. See, Mold Remediation in Schools and Commercial Buildings, U.S. EPA, Office of Air and Radiation, EPA 402-K-01-001, March 2001 (www.epa.gov/iaq/molds/index.html).

Potential Health Effects

The extent to which molds may cause health problems remains an unsettled question in the scientific and medical communities. Those who contend that mold adversely impacts human health implicate two distinct constituents of mold as the cause of negative health effects: 1) mold spores, which are present in most forms of mold; and 2) mycotoxins - compounds that help the mold digest food sources, such as wood - which are typically found in Stachybotrys, Aspergillus and Pennicilliummolds. Mold spores have been linked to allergies and upper respiratory irritations. According to the EPA, mycotoxin exposure has been linked generally to symptoms such as runny nose, cough, congestion, headaches, nose-bleeds, dermatitis, and other cold and flu-like symptoms. See, http://www.cpa.gov/iaq/biologic.html. Hundreds of different mycotoxin compounds exist, which scientists are currently attempting to identify and differentiate.

EPA recognizes some potential health impacts from exposure to molds. A 1994 EPA publication discusses the potential health effects of biological air pollutants generally and molds specifically:

Biological agents in indoor air are known to cause three types of human disease: infections, where pathogens invade human tissues; hypersensitivity diseases, where specific activation of the immune system causes disease; and toxicosis, where biologically produced chemical toxins cause direct toxic effects. In addition, exposure to conditions conducive to biological contamination (e.g., dampness, water damage) has been related to nonspecific upper and lower respiratory symptoms . . . .

However, mycotoxins are contained in some kinds of fungus spores, and these can enter the body through the respiratory tract . . . . Skin is another potential route of exposure to mycotoxins. Toxins of several fungi have caused cases of severe dermatosis.

Indoor Air Pollution: An Introduction for Health Professionals, Co-sponsored by: The American Lung Association, EPA, The Consumer Product Safety Commission, and The American Medical Association. U.S. Government Printing Office Publication No. 1994-523-217/81322, 1994 (author's parenthetical).

Even so, the presence of mold in a building does not necessarily mean that an occupant will either be exposed to it or suffer any adverse health effects. For a building occupant to be exposed to indoor mold, the mold spores or fragments must be released into the air and inhaled, ingested or otherwise contacted. Even then, most people are exposed to molds every day, and most suffer no adverse effects. See, Mold Remediation in Schools and Commercial Buildings, EPA, Office of Air and Radiation, EPA 402-K-01-001, March 2001 (http://www.epa.gov/iaq/molds/index.html).

Even if an individual is exposed to mold, the full effect of exposure to molds is uncertain and the subject of extensive scientific study and debate. As set out in another EPA publication:

Although some mycotoxins are well known to affect humans and have been shown to be responsible for human health effects, for many mycotoxins, little information is available, and in some cases research is ongoing. For example, . . . preliminary reports . . . suggested an association between pulmonary hemorrhage and exposure to Stachybotrys chartarum. Review of the evidence of this association at CDC resulted in a published clarification stating that such an association was not established.

Mold Remediation in Schools and Commercial Buildings, Appendix B, EPA, Office of Air and Radiation, EPA 402-K-01-001, March 2001.

Regulatory Developments

At this time, there are no established standards governing mold exposures. Neither the United States Environmental Protection Agency (EPA) nor the United States Centers for Disease Control (CDC) have promulgated regulations regarding mold exposure. The Occupational Health and Safety Act also does not prescribe permissible exposure limits for mold spores or mycotoxins. In fact, in December 2001, OSHA withdrew its Notice of Proposed Rulemaking concerning indoor air quality. That proposed rule aspired to establish standards for contaminants present in indoor air in the workplace, including molds and fungi.

Nevertheless, efforts are underway in the United States House of Representatives to pass a mold bill. In the proposed United States Toxic Mold Safety & Protection Act of 2002, HR 4855, EPA is required to issue guidelines by 2004 which, among other things:

• Help determine if mold could be a potential health hazard for those individuals living in a housing or building;
  
  
• Establish professional standards for professional mold inspectors, remediators, and testing labs;
  
  
• Require state licensing and certifying of remediators, labs, inspectors, risk assessors, and industrial hygienists; and
  Protect toxic mold remediators and inspectors from dangerous health hazards that result from performing their jobs.

Passage of the mold bill is questionable. However, it indicates increased awareness of and sensitivity to toxic mold issues.

Notwithstanding the absence of federal regulations, the State of New York has drafted guidelines for assessing and remediating mold in buildings. In 1993, the New York City Department of Health (DOH), the New York City Human Resources Administration (HRA), and the Mount Sinai Health Occupational Clinic convened an expert panel on Stachybotrys atra in indoor environments. The result was the 1993 publication of guidelines (updated in 2000), entitled "Guidelines on Assessment and Remediation of Fungi in Indoor Environments." The document addresses health issues, environmental assessment, remediation, and health hazard communication relating to indoor mold issues. It provides the only instructive policy and is cited extensively by those addressing remediation goals for mold cleanups. The document can be found at http://www.ci.nyc.ny.us/html/doh/html/epi/moldrpt1.html.

Diagnosis v. Determining Cause

The key issue in mold litigation is causation, and most cases will ultimately boil down to the classic battle of the experts. At this time, attempts to distinguish between litigation symptoms brought on by a common cold or allergy and those brought on by mycotoxin exposure can be challenging. There is not an accepted scientific method for distinguishing the signs of actual mycotoxin exposure.

For example, in the recent and highly publicized case, Mary Ballard, et al. v. Fire Ins. Exchange, et al., No. 99-05252, health effects were alleged as a result of exposure to Stachybotrys mold. In that case, plaintiffs alleged that they and their three-year-old son grew ill when their homeowners' insurer refused a claim to replace a buckled sub-floor caused by leaky plumbing. Ultimately, the house had to be torn down because mold impacts were too extensive to remediate. However, the medical science behind the claimed personal injuries did not withstand a Daubert/Robinsonchallenge.

In the plaintiffs' personal injury claims centered upon allegations that they had suffered brain damage from Stachybotrys mold exposure. The defense asserted that the science presented by plaintiffs' expert was not sufficiently reliable to establish that molds can cause injuries to the central nervous system or that the mold in the plaintiffs' home caused the brain injuries alleged. Plaintiff's epidemiological studies were largely inconclusive, and plaintiffs argued that scientific studies were not needed to prove general causation because testing subsequent to the epidemiological studies showed the existence of neurotoxins in the air of the home. The court excluded the mold expert's testimony and dismissed the personal injury claims. The court based the decision on the plaintiffs' failure to provide statistically valid epidemiological studies showing that mold exposure could affect brain function.

When scientific evidence is inadmissible, circumstantial evidence concerning the occurrence of symptoms and mycotoxin exposure may be the only evidence of causation. Therefore, the technical and scientific issues associated with demonstrating a causal connection between symptoms and exposure to mycotoxin are of significant interest in mold litigation cases.

Proving Causation and Related Science Issues

As the Ballard case illustrates, issues associated with proving causation are critical to mold cases. Essential elements of proving causation in a mold case are (i) reliable analysis and (ii) identifying the type and level of mold spores or mycotoxins to which the individual allegedly was exposed.

The Need to Sample

Normally, when mold is readily observed in a structure, it can be remediated without sampling. However, there are a number of circumstances when sampling may be necessary or appropriate. If a party seeks reimbursement or coverage under an insurance policy for the remediation costs, he or she may have to confirm the contamination to support the claim. Also, if an individual suspects mold contamination in a structure, and it is not detectable after a visual inspection, then sampling may be necessary to reveal evidence of mold spores. Additionally, if mold is being remediated and there is a question about how far the colonization extends, then surface sampling in combination may be useful to confirm that the complete mold colony has been remediated. Finally, if there are suspected adverse health impacts associated with mold, sampling should be undertaken to confirm the type or level of contamination.

Professionals experienced with mold issues and familiar with current guidelines should conduct any sampling. Even so, the available science regarding sampling and threshold levels of concern is incomplete and remains controversial. Although there are several available guidance documents, there are no clear benchmarks or standard values against which to compare testing results. Sampling without a specific purpose greatly increases the chances of generating useless data. If samples are taken, there should be a specific question that the sample results can help to answer.

Basic Sampling Methods

Sampling for mold spores can indicate whether the mix of indoor molds is typical or atypical of the outdoor mix, at least at the time the test is taken. Generally, indoor mold types should be similar to outdoor types and levels should be no greater than in outdoor areas. Conversely, the presence of certain species of mold indoors that are absent outdoors may indicate a mold program and degraded air quality.

Building on the growing awareness - or perhaps fear - of "toxic mold," numerous mold test kits have come on the market. While of limited utility for litigation purposes, these basic test kits can be an inexpensive first step to determine the presence of mold, as well as the specific type of mold. A professional or a layperson can conduct these tests. If a non-professional performs the sampling, the reliability of the sampling obviously will be difficult to defend. Three common methods of sampling utilize tape-lift surface sampling, settling plates, and culturing. Each has its benefits and limitations.

Tape-Lift Surface Samples

Surface sampling is used to confirm the nature of suspected growth on environmental surfaces. The tape lift sample also can be used to measure the relative degree of biological contamination, and identify the types of microorganisms and other biological agents present. See American Conference of Governmental Industrial Hygienists (ACGIH), Bioaerosols, Assessment and Control, Section 12.2.1. Surface tape sampling "may help investigators decide if further sampling is indicated and may help them formulate recommendations for remediation." Bioaerosols, Assessment and Control, Section 12.1.3.3.The tape lift method is analyzed by direct microscopy. Therefore, there is no need to grow the fungus in a culture media to identify it, and both the viable (living) and non-viable (dead) spores can be detected.

Settling Plate Techniques

It is uncertain whether a settling plate can help determine whether there is an airborne concentration of concern in a building. According to ACGIH, "settling plates do not collect airborne particles in a representative manner and do not reliably measure bioaerosol concentrations." "The settling of particles by gravitation onto a culture plate or a microscope slide depends highly on particle size and is influenced strongly by air movement. Given the unpredictable and uncontrollable nature of ambient particle movement, investigators cannot directly relate the number of CFUs [mold colony forming units] on a settling plate . . . to the concentrations of the corresponding particles in the sampled environment." Bioaerosols, Assessment and Control [ACGIH 1999], Section 2.3.2.2. For defensive air sampling, rather than relying on a settling plate, consider retaining a trained professional sampler.

Cultures

"Culture-based methods allow detection of only those organisms that are alive, in a condition to grow in culture, and able to successfully compete with the organisms in an environmental mixture. It is possible (and perhaps likely) that the majority of microorganisms in a particular sample are not identifiable with culture-based methods. The species most readily cultured from a given environment may not be the most prevalent or the most important species present." Bioaerosols, Assessment and Control Section 6.1.2.2. For example, slower-growers (like Stachybotrys) may be overgrown by molds that grow much more rapidly and thus may not be found by the culture technique. Therefore, as with settling plates, the usefulness of cultures in litigation is questionable.

Professional Air Sampling

Professional air monitoring may be necessary where previous sampling has confirmed the presence of mold and there is concern that mold spores have migrated through the subject building through the air handling system or through the ambient air. Air monitoring also may be necessary where the presence of mold is suspected, but cannot be visually located, such as mold growth behind walls. The sampler should be trained in proper air sampling methods for microbial contaminants. The sampler also should take care to use a laboratory specializing in mycology and to consult with the lab to ensure sample integrity during shipment.

Defensible Sampling Results

In mold-related litigation as in any other, reliable data exchanged between the adverse parties can go a long way toward resolving an issue. The use of a certified industrial hygienist or other experienced professional environmental sampler is imperative in mold litigation. Proper sampling and analytical methods and procedures must be followed and documented. Common sampling pitfalls that may occur during sampling include taking an inadequate number of samples and lack of outdoor control samples. It is also critical that consultants document that field sampling and laboratory equipment was sanitized prior to sampling and analysis. Chains of custody must be maintained and consulting or testifying experts retained to interpret and explain the results of the sampling.

Guidance Documents

There is also a plethora of helpful and not-so-helpful information on the Internet for plaintiffs, defendants, those searching for qualified consultants, or others concerned about mold in their surroundings. Two very helpful and extensively cited guidance documents in the literature on mold, and from which background information was drawn for this article, include EPA's March 2001 "Mold Remediation in School and Commercial Buildings," and the "Guidelines on Assessment and Remediation of Fungi in Indoor Environment" prepared by the New York City Department of Health, Bureau of Environmental & Occupational Disease Epidemiology. Both guidance documents are a good resource on mold assessment and remediation.

Elizabeth B. "Beth" Davis is Of Counsel with Womble Carlyle Sandridge & Rice, PLLC, resident in the firm's Atlanta office. Beth has extensive experience with counseling and litigation in all aspects of federal and state laws related to hazardous waste, underground storage tanks, water, air, and occupational safety. She can be reached at 404/962-7542 or at edavis@wcsr.com.

Brian E. Heim is Counsel, EHS and Logistics, for International Paper Company, resident in Memphis, Tennessee.

Stan B. Green is an associate with Womble Carlyle Sandridge & Rice, PLLC, resident in the firm's Winston-Salem office. Stan advises clients on state and federal environmental compliance and permitting requirements and environmental issues associated with corporate and real estate transactions. He also litigates toxic tort cases and issues arising under the federal and state environmental statutes and their implementing regulations. Stan can be reached at 336/721-3728 or sgreen@wcsr.com.